Some types of electronic circuits use relatively little power, and produce little heat. Circuits of this type can usually be cooled satisfactorily through a passive approach, such as convection cooling. In contrast, there are other circuits which consume large amounts of power, and produce large amounts of heat. One example is the circuitry used in a phased array antenna system. Others include other types of electronics, such as densely packed electronics used for current and future computational circuits, which can produce 1000-10,000 watts of heat per cubic centimeter, or more.
In the modern phased array antenna example, the system can easily produce 25 to 500 kilowatts of heat, or even more. Future computers are envisioned to produce equally large amounts of heat. One known approach for cooling this circuitry is to incorporate a refrigeration unit into the electronics cooling. However, suitable refrigeration units are large, heavy, and consume many kilowatts of power in order to provide adequate cooling. Although refrigeration units of this type have been generally adequate for their intended purposes, they have not been satisfactory in all respects. An equally important factor is the inability of existing methods to remove high flux heat loads from electronic components and modules. Existing approaches, which use a coolant flowing inside a coldplate or thermal plane to which electrical components and modules are mounted, have inadequate heat transfer performance to meet future needs. In addition, approaches using two-phase, sprayed fluorinerts are not satisfactory in all respects.